scsi: qla2xxx: Fix mailbox recovery during PCIe error

scsi: qla2xxx: Fix mailbox recovery during PCIe error

For the mailbox thread that encounters a PCIe error, pause that thread
until PCIe link reset/recovery has completed to prevent the thread from
possibly unmapping any type of DMA resource that might be in progress.

Link: https://lore.kernel.org/r/20210329085229.4367-10-njavali@marvell.com
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>